Eccentric adjustment for thermostats



G. A. HOBERTSHAW. ECCENTRIC ADJUSTMENT FOR THERMOSTATS.I

APPLICATION FILLED APR. l-4, T920. l v

Patented May 3, 1921. 82 SHEETS-SHEET l SI1-Luca Hoz G. A. ROBERTSHAW.ECCENTRIC ADJUSTMENT FOR THERMOSTATS.

I APPLICATION FILED APR. I4. 1920. 1,376,462. 1 Patented May 3,1921.

2 SHEETS-SHEET 2.

PATENT OFFICE.

GEORGE A. ROBERTSHAW, OF GREENSBURG, PENNSYLVAIA.

ECCENTRIC ADJUSTMENT :FORV THERMOSTATS.

Specification of Letters Patent.

Patented May 3, 1921.

Application led April 14, 1920. Serial No. 373,980.

T o all whom t may concern.'

Be it known that I, GEORGE A. ROB-EnrsHAw, a citizen of the UnitedStates, residing at Greensburg, Westmoreland county,

Pennsylvania, have invented a new and useful Improvement in EccentricAdjustments for Thermostats, of which the following is a full, clear,and exact description, reference being had to the accompanying drawings,forming part of this specification.

The present invention relates broadly to thermostats, and moreparticularly to an adjustment whereby the temperature effective foropening the valve controlled by the thermostat may be regulated.

The principal object of the present invention is to provide a fineadjustment for thermostats enabling the manufacturer to determine themaximum and minimum temperature settings possible.

A further object of the invention is to provide an adjusting device forthermostats whereby a customer is not able to make such a setting thatupon cooling the valve will be damaged.

A still further object of the present invention is to provide anadjustment for thermostats `of the type described in which the lostmotion usually present in ordinary screw adjustments is eliminated.

Another object of the present invention is to providean adjustmentcomprising an eccentric provided with a suitable dial by reason of whichit is impossible to lose the ori inal setting or point of adjustment.

till another object of the present invention is to provide an adjustmentenabling the valve setting' to be changed from a distant point.

The foregoing and other objects, together with their attendantadvantages, will be apparent as the invention becomes better understood,by reference to the accompanying specification and drawings forming apart thereof,it being premised that changes may be made in the variousdetails and the manner of operation, within the scope of the appendedclaims, without departmg from the sprit of the invention.

, Figure 1 is a side elevation partly 1n section of a portion of athermostat and the valve controlled thereby with my improved adjustmentintermediate the two.

Fig. 2 is a jartial sectional view on the l1ne II-II of ig. l.

Fig. 3 is a side elevation of a modified.v

form of adjustment.

F 1g. 4 is a view corresponding to Fig. 1 of a further modification, and

F 1g. 5 is a side view of a different arrangement 'of thermostat andvalve employing my 1mproved adjustment.

Where thermostats are utilized for controlling valves, it is desirableto effect a defi- Inite and accurate adjustment of the thermostatenabling it to be set for operation at certain predeterminedtemperatures. It is also desirable that these temperatures may bedetermined either before the valve is installed, or after the same isinstalled, and that means be provided for changing the setting.

Heretofore it has been customary to regulate thermostats by ordinaryscrew adjustments, which adjustments have been found in practice topermit a considerable amount of lost motion, thereby rendering thethermostat inaccurate to this extent. In addition, the ordinary screwtemperature adjustment, unless equipped with a stop, can be turned morethan one revolution. As it is difficult to furnish a satisfactory dialfor use after the screw has completed one complete revolution, it willbe apparent that the original setting is easily lost. By means of theeccentric adjustment as shown herein, it is impossible to lose theoriginal recording point of adjustment, as no matter how many times the`eccentric shaft is revolved, each complete revolution will restore theparts to their original condition.

A further disadvantage inherent in thermostats havingthe ordinary screwadjustment is the possibility of turning the screw so far that when thevalve cools, the levers will strike the body of the same and damage thevalve. By properly regulating the amount of eccentricity, themanufacturer can limit the maximum temperature at which the valve can beused,- thereby. p reventing damage to the valve by providlng at alltimes sufficient room in the yoke tov take up the movement of the leversfrom the closed position of the valve to the full open position thereof.

Referring more particularly to the drawings, there is illustrated inFig.1 a pipe line 2 having any desired type of valve 4 4 therein, andprovided with a yoke 5 adapted tocarrythe levers 6 and 7 and theexpansible element 8 of the thermostat. In constructions of this nature,the levers 6 and 7 are customarily positioned intermediate theexpansible element 8 and the valve stem 9 for'transmitting movement fromthe thermostat to the valve for opening the same.

It will be apparent that with a construction of this type, thetemperature at which the thermostat will be effective for opening thevalve may be controlled by moving the lever 7 in such a manner that itis either moved closer to the expansible element or away from the same.For accomplishing Y this movement there is provided an eccentric,illustrated in detail in Fig. 2, comprising a main body 10 having abearing 11 in -the yoke 5 andl provided with an eccentric pin orprojection 12 extending through the lever 7. At its forward end, themain body may be squared, as indicated at 14, enabling a wrench or otheradjustable device to be .applied thereto for changing the position ofthe pin or projection 12 and thereby adjusting the lever 7. To enablethe amount of adjustment to be accurately determined, the body member l0may have secured thereto a dial 15 of any desired construction andprovided with calibrations 'coperating with an index finger or pointer16.'

With the construction described it is possible to accurately adjust theposition of the lever 7 and thereby vary between minimum and maximumpoints the temperatures at which the thermostat is effective for openingthe valve. At the same time it is impossible to lose the originalsetting as the parts will be restored to their original positionsautomatically upon each complete revolution of thebody member 10. I

In Fig. 3 there is illustrated a slightly modified means forpadjustingthe position' of the eccentric. v As the.; neral construction of theparts-corresponds to that already described, they are indicated by thesame reference characterswith the letter a afiixed thereto. In the formshown in this figure, the body member or shaft 10a is provided with apinion 17 having calibrations thereon coperating with the index lingeror pointer 16a. A-F'ryoperating the pinion 17 there may be provided apin1on 18 meshing therewith and carried by a shaft l19 same.

which may be extended to any desired point and equipped with means forrotating the In some instances it is` desirable to have the pinion 18much smaller than the pinion 17 in ,order to furnish the necessary powerfor adjusting the thermostat. In other instances, however, the gearratio may be approximately the same as will be readily apparent..

thereto. In this construction the shaft 10b is provided with a wormwheel 20 adapted to be rotated by means of aworm 21 carried on the shaft22 journaled in the yoke 5". The shaft 22 may be elongated so as to beextended to a distant point', permitting adjustment of the valve whereit would otherwise be inaccessible. With this. construction also, acomplete rotation of the worm wheel 20 will restore the parts to theiroriginal setting, thereby preventing its original setting from becominglost.

In Fig. 5 the modified type of valve is illustrated as comprising asuitable base or bracket24, supporting at one end a valve 25 of anydesired construction, and at its opposite end a thermostat 26. Thebracket 24 may be provided with bearings 27 up.- standing-therefromV andadapted to receive the shaft 28 corresponding to the main body l 10beforedescribed. This shaft also carries an eccentric 29 extendingthrough thelever 30 coperatin with the valve stem 31 and the expansibleelement 32 of the thermostat. One end of the shaft 28 may be squared, asillustrated, and provided with a pointer 34 coperating with graduations35 on the bearing 27. By: rotating the shaft 28 the position of thelever 30 may be changed to vary the temperature at which the thermostatis effective for opening the valve. l v

It will be obvious that the various' constructions described andillustrated may, to a large extent, be interchanged and that otherchanges or modifications may be made within the scope of the claims.-

`The advantages of the present invention arise from a constructionpermitting accurate adjustment of the thermostat with-l -out thepossibility of damaging any of the4 j,

parts. Further advantages of the mventlon reside in the elimination ofthe lost motion usually. found in screw adjustments and-in aA valve, athermostat, a pivoted and rotatable means for changing the position'ofthe pivotal axis of said. lever, said means returning the pivotal axisto its original position upon a complete revolution thereof,substantially as described.

3. An adjustment for thermostats comprising a support, a lever pivotedtherein, and an eccentric for changmg the position of the pivotal axisof said lever, substantially as described.

4. An adjustment for thermostats comprising a support, a lever, aneccentric cooperating with said lever, and means for adjusting saideccentric, substantially as described.

5. An adjustment for thermostats comprising a support, a lever, a shaft-journaled in said support, an eccentric carried by said shaft andcoperating with said lever, and means for adjusting said shaft,substantially as described.

6. An adjustment for thermostats comprising a support, a lever, a Shaftjournaled in said support, an eccentric carried by said shaft andcoperating with said lever, means for adjusting said shaft, and

a dial for determining the amount of ad-v justment thereof,substantially as described.

7. Ay device of the claw described, comprising a valve, a valve stem, athermostat having an expansible element, a lever intermediate said valvestem and expansible element, and means or changing the position of saidlever, said means being, adapted upon continued operation in the samedil rection to restore the lever to its original position, substantiallyas described.

8. A device of the class described, com-Av prising a valve, a valvestem, a thermostat having an expansible element, a lever intermediatesaid valve stem and expansible element, means for changing the positionof 'l same has been moved a predetermined amount in the same direction,substantially as described. 10. A device of the class described,comprising a valve, a thermostat, ;av pivotal lever intermediate saidvalve and thermostat, means for changing the position of the pivotalaxis of said lever, and a gear for operating said means, substantiallyas described.

In testimony whereof I have hereunto set my hand.

GEORGE A. RoBERTsHAW.

